drm: Update the device-independent code to match Linux 3.8.13

This update brings few features:
o Support for the setmaster/dropmaster ioctls. For instance, they
are used to run multiple X servers simultaneously.
o Support for minor devices. The only user-visible change is a new
entry in /dev/dri but it is useless at the moment. This is a
first step to support render nodes [1].

The main benefit is to greatly reduce the diff with Linux (at the
expense of an unreadable commit diff). Hopefully, next upgrades will be
easier.

No updates were made to the drivers, beside adapting them to API
changes.

[1] https://en.wikipedia.org/wiki/Direct_Rendering_Manager#Render_nodes

r280814 is merged at the same time to avoid a short window where RANDR
might be broken:

drm: Import Linux commit 9bc3cd5673d84d29272fa7181a4dfca83cbb48c1

Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Fri May 31 12:17:08 2013 +0000

drm: Sort connector modes based on vrefresh

Keeping the modes sorted by vrefresh before the pixel clock makes the
mode list somehow more pleasing to the eye.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

PR: 198936 (r280814)
Tested by: Many people
MFC of: r280183, r280187 (original commit by glebius), r280814
Relnotes: yes

MFC r277487:
An update for the i915 GPU driver, which brings the code up to Linux
commit 4d93914ae3db4a897ead4b.

MFC r277959 (by adrian):
Fix backlight for ivybridge based laptops (and whatever else comes through
this codepath.)

MFC r278146:
Do not attach to the unsupported chipsets, unless magic tunable is
frobbed.

MFC r278147, r278148:
Fix sign for the error code returned from the driver-specific code.

MFC r278152:
Do not access gmbus_ports array past its end.

MFC r278159 (by emaste):
Remove duplicate intel_fbc_enabled prototype.

MFC r257869:

drm: Initialize "handle" to 0 before calling drm_gem_handle_create()

This is variable is being checked in drm_gem_name_create() before being
set.

Approved by: re (delphij)

drm: Update the device-independent code to match Linux 3.8.13

This update brings few features:
o Support for the setmaster/dropmaster ioctls. For instance, they
are used to run multiple X servers simultaneously.
o Support for minor devices. The only user-visible change is a new
entry in /dev/dri but it is useless at the moment. This is a
first step to support render nodes [1].

The main benefit is to greatly reduce the diff with Linux (at the
expense of an unreadable commit diff). Hopefully, next upgrades will be
easier.

No updates were made to the drivers, beside adapting them to API
changes.

[1] https://en.wikipedia.org/wiki/Direct_Rendering_Manager#Render_nodes

r280814 is merged at the same time to avoid a short window where RANDR
might be broken:

drm: Import Linux commit 9bc3cd5673d84d29272fa7181a4dfca83cbb48c1

Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Fri May 31 12:17:08 2013 +0000

drm: Sort connector modes based on vrefresh

Keeping the modes sorted by vrefresh before the pixel clock makes the
mode list somehow more pleasing to the eye.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

PR: 198936 (r280814)
Tested by: Many people
MFC of: r280183, r280187 (original commit by glebius), r280814
Relnotes: yes

MFC r277487:
An update for the i915 GPU driver, which brings the code up to Linux
commit 4d93914ae3db4a897ead4b.

MFC r277959 (by adrian):
Fix backlight for ivybridge based laptops (and whatever else comes through
this codepath.)

MFC r278146:
Do not attach to the unsupported chipsets, unless magic tunable is
frobbed.

MFC r278147, r278148:
Fix sign for the error code returned from the driver-specific code.

MFC r278152:
Do not access gmbus_ports array past its end.

MFC r278159 (by emaste):
Remove duplicate intel_fbc_enabled prototype.

MFC r257869:

drm: Initialize "handle" to 0 before calling drm_gem_handle_create()

This is variable is being checked in drm_gem_name_create() before being
set.

Approved by: re (delphij)